1. Field of the Invention
The invention relates to continuous deflected ink jet printing devices and, more particularly, in such devices, it relates to the part that has the function of acting electrically on the ink jet.
2. Description of the prior art
Deflected continuous ink jet printers are known, and one of them has been described in the French patent application No. 8913719 filed on 16th Oct. 1989 and entitled "Ink Jet Printing Head And Method For The Implementation Of This Head, Designed Notably For The Printing Of Large-Sized Characters".
In the above-mentioned patent, the head comprises the following in a single pack: at least two modulation elements comprising injection nozzles fed by a single ink circuit and a module for the recovery of unused drops, common to all the jets, with only one recovery outlet.
The single pack has a base used as a support for the modulation elements, charge electrodes, phase detection elements, and deflection electrodes, these different elements having to be aligned with a precision of the order of one-hundredth of a millimeter.
Now, such precision is very difficult to obtain when these elements are manufactured separately and then mounted on the base, and the difficulty of maintaining this precision increases with the number of ink jets of the printing head. Moreover, the number of adjustments to be made, notably adjustments of alignment, during the mounting and maintenance is high.
Besides, it can be seen that a printing head of this type is ill-suited to the making of a row of several tens of ink jets as the cost of manufacturing and maintaining such a system would be very high.
The object of the present invention is therefore the making, in a multijet printing device, of a deflection head, the manufacture of which is greatly simplified while, at the same time, it has high precision of positioning of the different elements.
Another object of the present invention is the making of a deflection head of the modular type that can be easily associated with one or more heads of the same type.
Another object of the present invention is the implementation of a method for the manufacture of modular type deflection heads.